Of one-half to



2 Sheets Sheet 1.

(No Model.) L. MOORE.

MAGNETOELEGTRIU BELL Patented Aug. 6., 1895.

(No Model.) 2 SheetsSheet 2.

L. MOORE. MAGNETO ELECTRIC BELL.

No. 544,107. Patented Aug. 6, 1895.

UNITED STATES PATENT OFFICE.

LELAND MOORE, OF BROOKLYN, NEW YORK, ASSIGNOR OF ONEHALF TO JOHN C. REILLY, OF SAME PLACE.

MAGNETO-ELECTRIC BELL.

SPECIFICATION forming part of Letters Patent No. 544,107, dated August 6, 1895.

Serial No. 545,284. (No model.)

To all whom it may concern:

Be it known that I, LELAND MOORE, a citizen of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Magneto-Electric Bells, of which the following is a specification.

' This invention is an improvement in magneto-electric bells for signaling and sounding an alarm, and it is specially useful with a telephone-subscribefis set of instruments.

The object of my invention is to quicken the responsive action of the bell, and also to intensify the sound. I do this by mechanically assisting the movement and byincreasing the momentum of the stroke or blow. In connection with an alternating-current magneto-generator my improved bell responds quicker, strikes harder, and emits a greater audible result, when operating upon a gong of any given size, than any other arrangement now known. To produce this desirable result I have devised an apparatus in which a fixed permanent magnet with bifurcated polepieces operates upon an oscillating singlespool electromagnet through the medium of a couple. The electromagnet is preferably cylindrical and is pivoted in trunnionbearings at diametrically-opposite points midway the poles. It has asoft-iron core,to which, at opposite ends, are adjustably fixed polepieces in the form of a keystone, and each pole-piece is covered with sheet-brass having sufficient resilience and so arranged as to initiate the return movement coincident with the initiation of the reverse current-impulse which causes the return movement. The pole pieces of the permanent magnet are four in number and are shaped to conform with the sides of the keystone pole-pieces. The fixed pole-pieces act as limiting-stops for the oscillating electromagnet,- contact being made with the non-magnetic spring sheet-brass with which the poles are covered or inclosed, as described. By changing the position of the keystone pole-pieces the extent of oscillation may be Varied. The winding of the electromagnet is so arranged that the free ends of the wire present themselves at the axial center of the coil, Where the movement is a minimum. Bythis means the wire is not liable to be broken by the continuous movementor oscillation and scraping or moving connections are avoided.

The accompanying drawings illustrate my invention.

Figure 1 is a plan view of my complete bell. Fig. 2 is a sectional view of the bell divided on the line shown in Fig. 1,and Fig. 3 shows the bell forming part of a telephone set.

C is an electromagnet, cylindrical in form, having a soft-iron core 0. At or near the center of the major axis there is a partition, preferably of insulating material 20, as hard rubber, having bearings 21 for the pivots 12 and 13 upon opposite sides thereof. The magnet is wound with insulated wire, so that the coil ends terminate at the central point 20, extending thence in helical coils to screw-posts 14t and 15, of sufficient height to bring the tops of the posts into the horizontal plane of the upper surface of the coil. The ends of the core 0 project slightly and are furnished with pole-pieces in the form of .a key stone, 9 and 19. Each core end is shaped to fit a slot in its pole piece and is provided with a screwthread to receive a screw or bolt or nut, as 11, operating to hold the pole-pieces in a fixed position. Upon each pole-piece and inclosing it upon three sides is a section of nonmagnetic metal, such as spring sheet-brass 10. (See Fig. 1.) The depending sides of the brass piece 10 are at an acute angle with respect to the sides of the pole-piece 9, so that the brass piece has a spring-like action.

Wis a base-board of wood. b is a U-shaped brass strap fixed to the base W.

P is a permanent magnet having its polar ends fixed to the free ends of the brass strap upon the interior side thereof. Pole-pieces of soft iron are fixed to each pole of permanent magnet P, thereby becoming permanently magnetic and constituting the permanent magnet, one having bifurcated or divided pole-pieces, bifurcations 5 and 6 being of, say, north polarity and bifurcations 7 and 8 being of south polarity. These four polepieces are in close proximity to the keystone pole-pieces of magnet-coil O, oscillating upon pivots 12 and 13, the latter fixed, respectively,

to the permanent magnet P and the brass strip 1). A hammer or striker h is fixed to the elcctromagnet C, and gongs B are placed upon opposite sides of the free end thereof.

In Fig. 3, L is a telephone-line extending from the magneto alternating-current calling-generatorM, forming part of a telephonesubscribers set at one station, to a telephonesubscribers set in the other station, both stations being similarly equipped, a telephone T and a transmitter if being in one branch and the calling device and magneto-bell being in a second branch, with a switch G operated by the influence of the telephone to connect the line to one branch or the other, as desired.

It is to be noted that in addition to the benefits due to the construction of this bell heretofore described the magnetism of the permanent magnet is preserved by the use of the core cas a keeper, for no matter in which position the core 0 may come to rest the magnetic circuit between the poles of P is always closed through the core 0. This operates to prevent loss of magnetism according to well-known scientific principles.

hen the armature of generator M is r0- tated short impulses of opposite polarity pass over L to the magneto-bell.

Let us assume that poles 5 and 6 are north and 7 and 8 are south. A positive impulse renders the pole 9 of 0 south and the opposite pole 19 north. Permanent pole 6 attracts 9 and permanent pole S attracts 19, imparting a turning movement to the coil. Hammer h strikes the gong B, and the brass spring-like pieces 10 on both poles are depressed against the pole-pieces. During the short interval of no current, pending the establishment of a reverse impulse, the resilience of the springbrass starts the magnet-coil on its return oscillation, and the reversed impulse of current changes pole 9 to north and pole 19 to south. 9 is repelled by 6 and attracted by 7, While 19 is repelled by S and attracted by 5. The weight of the electromagnet and its speed of movement, under the combined influence of the spring and current, give it a momentum Which results in a sharp and comparatively heavy blow. This bell is Well adapted to use as an eXtension-bell-that is, a bell used when the bell branch of the subscribers set is extended to a second point or station, when tWo bells are used in the same branch. In

such cases, while the work is doubled, the

current is decreased and a more eificient device is necessary to produce a satisfactory result.

WVhat I claim, and desire to secure by Letters Patent, is-

1. In a magneto-electric bell the combination of an electro-magnet pivoted at or near the central point of its major axis, four per manently magnetic pole pieces arranged in pairs of similar polarity, one pair upon each side of said axial line, one or more pole pieces for said electro-magnet in the form of a keystone, adjustably connected to said electromagnet, non magnetic springs in the form of a sheet or blade, each fixed to a pole piece and located between the poles of the permanent magnet and the electro magnet whereby the oscillating return movement of the electro-magnet is initiated and accelerated, a hammer fixed to said electro-magnet and a gong or sounding device therefor, arranged and operating substantially as described.

2. In a magneto-electric bell the combination of an electro-magnet pivoted at or near the central point of its major axis, four permanently magnetic pole pieces arranged in pairs of similar polarity, one pair upon each side of said axial line, one or more pole pieces for said electro-magnet, sheets of spring brass fixed thereto in position to make contact with the poles of the permanent magnets and initiate the oscillating return movement, a hammer fixed to said electro-magnet and a gong or sounding device therefor, substantially as described.

3. In a magneto-electric bell the combination of an electro-magnet or spool pivoted at or near the center of its major axis, permanent magnetic poles fixed, respectively, upon opposite sides of each pole of said electromagnet, and pole pieces for said electro-magnet, in the form of a key-stone, adjustably connected thereto, whereby the extent of oscillating movement may be varied by varying the position of the key-stone pole piece, a hammer fixed to said electro-magnet and a gong or sounding device therefor, substantially as described.

LELAND MOORE.

Witnesses:

J. O. REILLY, W. S. PLACE. 

